Contact



Dec. 15, 1942.

A. M. DRAVING con'rAc'r Filed July 1, 1939 gay II V

Patented Dec. 1S, 1942 Arthur M. Draving, Feasterville, Pa, assignor, bymesne assignments, to Penn Electric Development Corporation,Philadelphia, Pa, a corporation of Pennsylvania Application July 1,1939, Serial No. 282,452

1 Claim.

This invention relates to metallic contacts for the reception of plug indevices.

There have been many contacts developed in the past which were of moreor less effectiveness for large prongs, but which are ineffectual withthe relatively small prongs of the present day. In all prior artdevices;so far as known, the contacts, if efl'ectlve for a relatively fewinsertions of prongs, soon lost this effectiveness with repeatedinsertions and withdrawals. This, in large measure, was due to the shorthinge action radius, so to speak, of flexation of contact arms relativeto a backing plate from which they arose, among other objections.

It is among the objects of this invention to provide an improved contactfor the reception of a prong contact of a plug-in device; to provide acontact of enhanced resilience; to provide a contact with a wide rangeof adaptability as regards the size of prongs associatable therewith; toprovide a female contact with large expansive capacity without effectinga changeof setting of the metal; to provide a contact for gripping amale prong with two relatively bodily movable members as opposed torelatively axially hinged movements of certain prior art devices; toprovide a contact of improved electrical engagement with a male prong;to provide a contact having an improved guiding sliding engagement withan inserted prong; to provide a contact device having a plurality ofpoints of set or relative rigidity whereby the springing function is asa re-. sultant of flexing of a plurality of areas between set points; toprovide a contact, the movablev members of which swing on effectivepivots widely spaced from the edges of the members; to provide a contacthaving in effect a pair of convergent resilientarms, at the free ends ofwhich substantially cupped hands, functioning as contacting members, arearranged in opposed juxtaposition and arranged for bodily separationwhen a prong is forced between the hands to estab lish engagementtherewith; to providea contact having, external to and connecting itsprong receiving members,- spring means divided by bends into a pluralityof distinct resiliently functioning portions; and many other objects andadvantages as will become more apparent as the description proceeds.

In the accompanying drawing:

Fig. 1 represents a plan of an illustrativesocket with a contactaccording to this invention shown in dotted and full lines in positiontherein. Fig. 2 represents a plan of a blank from which the preferredform of contact according to this invention, is formed.

Figs. 3, 4, 5 represent respectively a plan, a front elevation and aside elevation of a contact formed from the blank of Fig. 2.

Figs. 5A and 53 represent respectively fragmentary vertical sectionsthrough a two piece supporting base, of the so-called laminated type,showing the perfect adaptability of the contact of Figs. 2 to 5, to suchtwo piece associations.

Fig. 6 represents a transverse vertical fragmentary section through amolded socket such -as shown in Fig. 1, with a contact according to Fig.5, in side elevation therein, to show the relationship.

Fig. 7 represents a fragmentary transverse section through a molded basesuch as on line 1-1 of Fig. 6, showing a plurality ofcontacts accordingto Fig. 3, in plan therein.

Fig. 8 represents a fragmentary vertical section through the moldedsocket or base, taken on line 88 of Fig. 1, showing two adjacentmodified contacts and their inter-engaging supporting relations with thebase, with one of the contacts partially broken away.

Fig. 9 represents a plan of a blank from which the modified form ofcontact of Fig. 8 is formed.

' Figs. 10, ll, 12 represent respectively a plan, a front elevation anda side elevation of the modified form of contact.

Fig. 13 represents a fragmentary elevation of a plug-in device with aprong contact thereon just entering the contact of Fig. 11, shown infront elevations.

Fig. 14 represents a transverse section on line |4l4 of Fig. 6, but withthe contact shown in exaggerated spaced relation in full'lines to showin dotted lines the substantial flexation of the componentparts of thecontact in adapting itself to the reception of a contact prong shown indotted lines, the spacing exaggeration failing to disclose that, thereis an actual sliding guiding relation of the contact and aperture withcomparatively little tolerance or play.

Fig. 15 represents a transverse section through a slightly modified formof a contact exemplifying the invention herein. f

The socket in of Fig. 1 may be of any sort or nature, but illustrativelyis of the type applicable to use with a radio tube of the so-calledoctal" type, having a center guide recess II and a plurality of prongreceiving apertures l2 into each of which the prongs, as for instancethe prong l3 of Fig. 13, arranged in an annular row, are rerepresentssubstantially and which is permitted despite the practically tightguiding sliding engagement of the contact' in the aperture or recess l5,the curvature of the side arms or walls 36, as indicated in dotted linesin exaggerated flexation in Fig. 14, and which again is permitted,despite the lateral sliding guiding engagement of the side walls 36 'inthe merges into the enlarged longitudinal bore 9 which runs completelythrough the base below the aperture l2, normal to the exposed face l4thereof. The open side of recess or bore 9 in line radially thereof,merges into a parallel contact recess l5 which extends upwardly from thelower face It of the base, laterally in communication throughout itslength, with the prong aperture extension 9, to terminate below a wallportion i1, forming part of 'the surface [4. The respective wallportions l1, one for each prong aperture, are preferably arranged in aring concentric to the ring of apertures, and adjacent wall portions Hare spaced by facial recesses l8 extendingdownwardly far enough tooverlap laterally the upwardly extending respective contact recesses 15.This forms lateralapertures 2|! leading transversely from contact recessIE to the floor 2| of recess l8. Preferably the floor 2| is divided intotwo halves by the rib 22 extending radially of the socket across therecess l8.

The blank 23 of Fig. 2 is generally T shaped in profile and is providedwith a cross piece 24 from which two tabs 25 project perpendicular tothe upper edge 25. The cross piece 24 merges into a shank 21 of reducedwidth, preferably having a median elongated slot or aperture 28 betweentwo parallel edges 30,and the shank is prolonged into a soldering tail3|, having one or more median apertures 32.

The blank is bent along the dot and dash lines 33, just inside the tabsor ears 25, to form a rough like device comprising a backing wall 34 andshallow side edges 35 adjacent to or terminating in the edges 30, and atthe upper end of the contact being continued in the side walls 36. Theblank is also bent about dot and dash line 31 to bring the outerextremities of the cross piece of the blank toward each other to definea generally triangular space, of which the backing plate is the base,and which are in effect arms brought together in front of the body, andthe free ends of the cross piece, from about dot and dash line 40, aresubstantially arcuately oppositely curved longitudinally of the contactas at 4| and 42 to form. the double walled prong receiving contactmaking portion of the contact, whichin effect cupped hands on the end ofthe arms. Preferably the upper end of each contact half 4| and 42 isslightly flared outwardly as indicated at 43. The ears or tabs 25 arebent over to a position acutely divergent from the side walls 35 as at25 in Fig. 4.

It will be apparent that the resilient set the contact-making portion 4|and 42 of the contact, is not dependent solely, nor even appreciably,upon a single hinge action relative to a stiff immovable base wall, asin the conventional type of contact, comprised for instance of atriangular or oval'prong channel in which a backing portion has armsbent toward convergence to define the channel. Instead the arms 4| and42 have a mutual relative flexation incident to the slight bending ofthe rear wall 34 in a curvature out of the initial plane of the wall(and which obviously may be varied predeterminedly by the introductionof slots and slits and the like, or as cut down in the blank of Fig. 9,

or the like),

recess I5, as this is relatively a small flexation or distortion. Itwill usually occur that it is easier to flex the adjacent walls than theactual comer which has acquired a set or rigidity, although there willalso occur some degree of fiexation aboutthe corners 33, 31 and 40 inany distortion of the contact. The greater degree of resilient curvatureor fiexation will probably occur in the converging arms, between thecorners 31 and 40, and there will also be some degree of bending of thehands or opposed faces 4| and 42, so that the forced insertion of aprong is in the contact will cause the contact to assume sub stantiallythe position shownin dotted lines in Fig. 14, and represent asubstantially bodily rela-v tive movement apart of theopposed cuppedfaces 4| and 42, each about an effective substantially long radius, aswell also, as about some additional shorter radii. The whole assembly issuch that great resilience is attained, and a strong and constantresilient engagement of the arcuate walls of the prongis experienced.Moreover, the spreading of the distortion over great area prevents undueworking of any portion so that the initial set of the contact remainssubstantially unimpaired even after a great multiplicity of insertionsand removals. It will be understood that in effect the prong receivingmembers are provided with spring means for maintaining a grippingtension. In a further subdivision as will be shown, the external springmeans is divided into a plurality of portions by bends.

With the blank of Fig. 2-bent to the shape of Figs. 3, 4 and 5, andinserted upwardly into the contact recess IS, with the prong engagingportions 4| and 42 disposed in the prong aperture I2, the tabs 25 areresiliently collapsed by the side walls of the contact recess |5 untilthelateral windows 20 are reached, when the upper edge 26 abuts the topwall portion I! after which the ears 25 expand until their tip endsengage the floor 2| of the recesses I8, when the contact is anchoredsecurely in the socket. It will be understood that although the prongcontact portion itself is not supported directly, yet the spread ears 25locked against outward movement by the recess floor 2| on each side ofthe backing portion and the latter having a wide bearin against thecontact recess wall, due to a substantially sliding guiding fit therein,the support of the contact is secure.

Obviously the engagernent of aprong in the contact portions 4| and 42depending upon the degrees of relative curvatures of arms. and prongswill have a firm line of wiping engagement on each side of the prongwith a minimum of contact resistance. Obviously .the closer the radiusof the prong approaches the radius of the arms, the

greater the contrasting areas and the greater the departure from thethin line contact, so this will be varied to suit requirements.

Referring to Figs. 5A and 53 a lower plate L has a contact receivingrecess 9 and |5' in which a contact according to Fig. '2 is disposed,hanging upon the ears 25, which extend perpendicularly instead ofacutely as in the form first described. The ears overlie the plate L andprevent the contact irom being pushed out. A

superposed plate of insulating material U having a prong receivingaperture l2, aligned with the gripping portions of the contact only, inthe composite recess 9 and I5, is clamped on cars 25, substantially, oris mounted in such relation as to permit appreciable axial movement ofthe contact, as will be clear.

.In the-blank of Fig. 9 the construction is similar to that of Fig. 2except that the upper end of the blank on edge 44. in place of externalears, has a median recess 45, the lateral boundaries of which are formedby the ears 46 extending from the edge 44 longitudinally to severancefrom the recess edge 48 and laterally being separated rrom the metal ofthe cross piece by the axially extending .slits 41. This construction isotherwise just like that of Fig. 2 and when the contact is bent to shapeit is just like that of the earlier figures except that the upper end ofthe backing portion is removed, with enhanced resilience for the armsarising therefrom, and the ears 46 come out the side walls 36 instead ofout of the end thereof. This form of contact has an enhanced resilienceand also saves metal in the formation of the blanks.

It will be evident that the advantages of the arms and cupped hands maybe secured with a different number of bends or corners. than thatdisclosed in the previous figures, as for instance by providing morecomers, or by providing less. In Fig. 15 a modification using a fewernumber of corners is disclosed as comprised of a backing portion 50having the acutely divergent side arms 5| and 52 bent therefrom aboutangular corners 53, and the arms terminate through corners i4 5 in theoppositely cupped hands or contact portions 55 and 56. The separation ofthe arms I55 and 56 is on effectivelong radii,- although not aseffective for the purpose as is the disclosure in Fig. 14. The operationand functioning of the the slots or slits in the backing plate orportion varies the resilience of the entire arm mounted thereon.

It will further be observed that the contact is arranged for a quick andeasy guided automatic locking into mounted position subsequent to mereinsertion into the contact recess from the lower end thereof.

The various further modifications that will occur to those skilled inthe art will be obvious and such are to be construed as within the scopeof the invention, unless otherwise expressly limited in the appendedclaim.

I claim: a i

In radio sockets, a socket base having a contact receiving aperture inone face extending partially through the face to a transverse walladjacent to the opposite face and a prong receiving aperture in saidopposite face extending completely.

through the base in communication with but relatively offset from thecontact receiving aperture, the contact'receiving aperture having a pairof shoulder ledges extending from its opposite sides, a contactcomprising a one piece metallic member disposed in the contact receivingaperture and formed by a back wall and two convergent jaws projectinglaterally from said wall in juxtaposed relation, the jaws disposed inconfronting relation in axial. alignment with the prong receivingaperture, like end portions of each jaw extending axially well beyondthe end of said back wall above said shoulder ledges to form freelyexpansible parts while the like opposite end porincreases or enhancesthe resilience thereof and tions of each jaw connect to the back portionwith restricted expansibility, whereby a prongentering said jaws throughsaid prong receiving aperture is clamped by successive stages offlexibllity, and integral tongues struck out of the first mentioned endportions. of the jaws from points above the end of the back walloverhanging the respective shoulder ledges to support the contact in thecontact receiving aperture against axial movement in one direction,while said wall provides an abutment for substantially preventing axialmovement of the contact in the other direction.

ARTHUR M. DRAVING.

